
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      body {
        transition: background-color 0.5s;
      }

      .sidenav {
        height: 100%;
        width: 0;
        position: fixed;
        z-index: 1;
        top: 0;
        left: 0;
        background-color: #111;
        overflow-x: hidden;
        transition: 0.5s;
        padding-top: 60px;
      }

      .sidenav a {
        padding: 8px 8px 8px 32px;
        text-decoration: none;
        font-size: 25px;
        color: #818181;
        display: block;
        transition: 0.3s;
      }

      .sidenav a:hover,
      .offcanvas a:focus {
        color: #f1f1f1;
      }

      .sidenav .closebtn {
        position: absolute;
        top: 0;
        right: 25px;
        font-size: 36px;
        margin-left: 50px;
      }

      #main {
        transition: margin-left 0.5s;
        padding: 16px;
      }

      @media screen and (max-height: 450px) {
        .sidenav {
          padding-top: 15px;
        }
        .sidenav a {
          font-size: 18px;
        }
      }
    </style>
  </head>
  <body>
    <div id="mySidenav" class="sidenav">
      <a href="javascript:void(0)" class="closebtn" onclick="closeNav()"
        >&times;</a
      >
      <ul>
        <li><a href="#">About</a></li>
        <li><a href="#">Services</a></li>
        <li><a href="#">Clients</a></li>
        <li><a href="#">Contact</a></li>
        <li><a href="#">Contact</a></li>
      </ul>
    </div>

    <div id="main">
      
      <span style="font-size: 30px; cursor: pointer" onclick="openNav()"
        >&#9776; open</span
      >
    </div>
  </body>
</html>
<script>
  function openNav() {
    document.getElementById("mySidenav").style.width = "250px";
    document.getElementById("main").style.marginLeft = "250px";
    document.body.style.backgroundColor = "rgba(0,0,0,0.4)";
  }

  function closeNav() {
    document.getElementById("mySidenav").style.width = "0";
    document.getElementById("main").style.marginLeft = "0";
    document.body.style.backgroundColor = "white";
  }
</script>
